SEARCH

SEARCH BY CITATION

Keywords:

  • Market period;
  • Minor components;
  • Quality;
  • Virgin olive oil

Abstract

The aim of this research was to study the relevance of the stability of minor components in commercial Spanish extra virgin and olive oil (OO) categories, particularly with respect to the individual phenolic compounds, tocopherols (vitamin E) and volatile compounds, during the market period (12 months). The study was carried out classifying several commercial olive oils (n = 39) according to their content in phenolic compounds into three different groups: extra virgin olive oils with high (>290 mg/kg; HP-VOO) and low (<210 mg/kg; LP-VOO) phenolic level and OO, due to the impact of biophenols on oxidative stability, sensory properties and nutritional aspects. After a market period of 1 year, the α-tocopherol content fell significantly (25–30% of its initial content) in the commercial oils. While the decrease in total phenolics and o-diphenols was not statistically significant, a relevant increase (33% on average) in simple phenolics (hytroxytyrosol and tyrosol) was observed in all the studied samples, suggesting its use as freshness or ageing marker. Throughout the market period, a low oxidation rate and therefore a high stability of the products was observed. Moreover, the results found in the study suggest that a higher market price OO is apparently related to better quality and process control, giving a superior final product in terms of its content of minor components related to organoleptic properties.

Practical applications: The quality of virgin olive oil – mainly its sensory characteristics and nutritional value – is directly related to its content in minor components, in particular phenolics and volatile compounds, and therefore to their stability during the market period. Nevertheless, this information is not available to consumers. As a consequence, it is very important for both producers and consumers to clarify and establish the real relevance of the stability of minor components in commercial olive oil categories during their shelf-life: how long they will keep their stability, organoleptic and nutritional characteristics. This information would highlight the individual quality properties of a specific oil product, beyond the sometimes misleading commercial category.